The study on the community structure of entomogenous fungi in a Masson's pine forest having been inoculated with Beauveria bassiana for many years showed that there were 4 genus and 7 species of entomogenous fungi, among which, B. bassiana was the dominant species, occupying 63.22% of the total, followed by Paeciloniyces (25.86%), Metarhizium (9.20%) and Verticillumn (1.72%). In terms of insect host diversity, the Brillouin index and evenness index were 3.564 and 2.315, and 0.814 and 0.865 for B. bassiana and P. cateniannulatus, and 1.471 and 0.862, and 0.963 and 1.000 for P. farinosus and V. lecanii, respectively, while M. flavoviride, M. anisopliae, and P. fumnosoroseus had lower diversity and evenness. The diversity index of insect hosts infected by B. bassiana showed a temporal variation, i.e., higher in spring and autumn, and lower in summer, which reflected the seasonal dynamics of B. bassiana population.